E4D Dentist is a chair-side CAD/CAM system capable of scanning in the mouth, from an impression or on a model. A laser is used to scan the preparation, preoperative condition, approved provisionals or diagnostic wax-up. DentaLogic software and Autogenesis are used to create a 3-D virtual model and proposed restoration compatible with the neighboring teeth and opposing dentition. Multiple design tools allow the user to manipulate the virtual tooth and a multi-color display shows strength of occlusal and interproximal contacts as well as material thickness. The E4D mill uses two of the three Two-Striper (Abrasive Technology) diamond burs under constant water spray to fabricate the final restoration from porcelain or composite blocks (from Ivoclar Vivadent or 3M ESPE). The E4D Mill features a proprietary automatic bur changer and a variety of prompts to direct the user in operating the mill and complete diagnostic and maintenance procedures. For customer support, Support on Sight (SOS) is a team of experienced dental professionals, software and hardware specialists who are able to remotely access your system and assist you during every aspect of the scan, design and milling process.
Suggested Retail Cost
Success with CAD/CAM, as with all dental restorative processes, begins with proper tooth preparation and tissue retraction. Imaging and creating a clear working three-dimensional model are best achieved when the prepared tooth has smooth line angles, proper line of draw and the margin is clearly visible. The initial training and access to the SOS support team significantly reduced the learning curve. As users gain experience and familiarity with the system, the design becomes more intuitive and ideal results are achieved more readily. Software updates such as Rapid Scan (automatic scanning function) further reduce the time needed to fabricate a restoration. The ability to scan in the mouth, from an impression or from a model enables the operator to use E4D with every patient (Fig 1). Because of these capabilities, use of the E4D was possible in challenging situations such as excessive salivary flow, limited opening, and a strong gag reflex which could limit use of other technologies.
IPS e.max CAD (Ivoclar Vivadent) restorations were fabricated for most full-coverage molar restorations, while IPS Empress CAD (Ivoclar Vivadent) was most often used for fabricating crowns in the premolar and anterior regions as well as for inlays, onlays and ¾ crowns throughout the mouth (Fig 2 and 3).
IPS Empress CAD and IPS e.max CAD (Ivoclar Vivadent) ceramic blocks were used. IPS Empress CAD is available in high and low translucency, as well as a multi-shade block with a gradient of high to low chroma within the block. IPS e.max CAD is available in high and low translucency blocks. The excellent fit of the restorations was the result of proper retraction, accurate imaging, advanced Autogenesis software and the ability of the assistant to utilize the design tools (Fig 4). Slight adjustment of proximal contacts or occlusion is sometimes necessary and easily achieved. The variability in need for adjustment is a result of the level of experience of the dentist or assistant doing the design, tooth preparation, parameter settings, and sprue location (Fig 5). All restorations were clinically acceptable and were bonded with MultiLink Automix Easy (Ivoclar Vivadent).
The E4D Mill produced ceramic restorations that were rated excellent for fit to the tooth. Clearly defined margins, proper reduction and slightly tapered walls allow ideal seating of each restoration. The quality and accuracy of the restoration margins are dependent on adequate soft tissue retraction and accurate margin marking during the design phase. Restoration margins were observed to be excellent when placed into the mouth. IPS Empress CAD and IPS e.max CAD (Ivoclar Vivadent) are both known for their exceptional esthetics and ability to blend with natural tooth structure. While Autogenesis provides proposals with very good anatomy, the operator can create deeper grooves and enhance the occlusal morphology using many design tools. E4D Mill also has a third detailing bur that allows the deeper grooves and thin margins to be milled with accuracy.
Forty-one restorations were evaluated at 12 months after placement. Results for fit, esthetics, margin accuracy and anatomy are shown (Fig 6).
One IPS Empress CAD restoration fractured and required replacement. One IPS e.max CAD restoration debonded and was recemented. No chipping was noted on any of the restorations. Most of the intracoronal restorations were finished with ceramic polishers, while most of the crowns (IPS e.max CAD) were stained, glazed and crystallized. The glazed restorations maintained their luster, and the polished restorations were sufficiently glossy (Fig 7).
E4D Dentist and Mill were used to fabricate 250 restorations, 41 of which were evaluated at 12 months after placement. Through proper training, access to the SOS team and the capabilities of the design center and mill, the consultants and assistants were able to effectively and efficiently fabricate excellent indirect restorations in a single patient visit. At one-year recall, the majority of E4D restorations received excellent ratings. IPS Empress CAD and IPS e.max CAD ceramics exhibited excellent esthetics, showed no signs of wear, and blended well with the surrounding tooth structure in nearly all restorations. At one-year recall, only one onlay showed staining at the cavosurface margin. No post-operative sensitivity was reported at one year.D4D Technologies, CAD CAM In-office System